/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 30318
 * Date: 2023-11-14
 * Time: 16:02
 */
public class Foo {
    public static void main (String [] args) {
        StringBuffer a = new StringBuffer ("A");
        StringBuffer b = new StringBuffer ("B");
        operate(a,b);//调用了Foo类的一个类方法
        System.out.println(a + "," +b);
    }
    static void operate (StringBuffer x, StringBuffer y) {
        x.append(y);
        y = x;
    }
}
